Asymmetric synthesis of highly functionalized tetrahydropyrans via a one-pot organocatalytic Michael/Henry/ketalization sequence.
Asymmetric synthesis of highly functionalized tetrahydropyrans via a one-pot organocatalytic Michael/Henry/ketalization sequence.
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DOI：
10.1021/ol501236a
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发表时间：
2014-07-18
期刊：
影响因子：
5.2
通讯作者：
Enders D
中科院分区：
文献类型：
--
作者：
Hahn R;Raabe G;Enders D
描述了非对映体和对映体选择性Michael/亨利/缩酮化序列以官能化四氢吡喃。多组分级联反应使用乙酰丙酮或β-酮酯、β-硝基苯乙烯和炔基醛作为底物，得到具有五个连续立构中心的四氢吡喃。使用双功能奎宁基方酰胺有机催化剂，在一次结晶后以中等至良好的产率（27-80%）、优异的对映体过量（93- 99%ee）和高非对映体比率（dr > 20：1）获得标题化合物。
A diastereo- and enantioselective Michael/Henry/ketalization sequence to functionalized tetrahydropyrans is described. The multicomponent cascade reaction uses acetylacetone or β-keto esters, β-nitrostyrenes, and alkynyl aldehydes as substrates affording tetrahydropyrans with five contiguous stereocenters. Employing a bifunctional quinine-based squaramide organocatalyst, the title compounds are obtained in moderate to good yields (27–80%), excellent enantiomeric excesses (93–99% ee), and high diastereomeric ratios (dr > 20:1) after one crystallization.